The ideal electrolyte for the widely used LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811)||graphite lithium-ion batteries is expected to have the capability of supporting higher voltages (≥4.5 volts), fast charging (≤15 minutes), charging/discharging over a wide temperature range (±60 degrees Celsius) without lithium plating, and non-flammability^1,2,3,4. No existing electrolyte simultaneously meets all these requirements and electrolyte design is hindered by the absence of an effective guiding principle that addresses the relationships between battery performance, solvation structure and solid-electrolyte-interphase chemistry⁵. Here we report and validate an electrolyte design strategy based on a group of soft solvents that strikes a balance between weak Li⁺–solvent interactions, sufficient salt dissociation and desired electrochemistry to fulfil all the aforementioned requirements. Remarkably, the 4.5-volt NMC811||graphite coin cells with areal capacities of more than 2.5 milliampere hours per square centimetre retain 75 per cent (54 per cent) of their room-temperature capacity when these cells are charged and discharged at −50 degrees Celsius (−60 degrees Celsius) at a C rate of 0.1C, and the NMC811||graphite pouch cells with lean electrolyte (2.5 grams per ampere hour) achieve stable cycling with an average Coulombic efficiency of more than 99.9 per cent at −30 degrees Celsius. The comprehensive analysis further reveals an impedance matching between the NMC811 cathode and the graphite anode owing to the formation of similar lithium-fluoride-rich interphases, thus effectively avoiding lithium plating at low temperatures. This electrolyte design principle can be extended to other alkali-metal-ion batteries operating under extreme conditions.

_{广泛应用的LiNi 0.8} Mn _0.1 Co _0.1 O ₂ (NMC811)||石墨锂离子电池的理想电解液有望具备支持更高电压（≥4.5伏）、快速充电（≤15分钟）、充电/在宽温度范围（±60 摄氏度）内放电，无需镀锂，且不易燃^1,2,3,4。没有现有的电解质同时满足所有这些要求，并且由于缺乏解决电池性能、溶剂化结构和固体电解质界面化学之间关系的有效指导原则，电解质设计受到阻碍⁵. 在这里，我们报告并验证了一种基于一组软溶剂的电解质设计策略，该策略在弱 Li ^{+之间取得平衡}–溶剂相互作用、足够的盐离解和所需的电化学以满足上述所有要求。值得注意的是，当这些电池在 -50 度下充电和放电时，面积容量超过每平方厘米 2.5 毫安小时的 4.5 伏 NMC811|| 石墨纽扣电池保持其室温容量的 75%（54%）摄氏（-60 摄氏度）在 0.1C 的 C 速率下，NMC811||石墨软包电池采用贫电解质（2.5 克/安培小时）实现稳定循环，在 -30 时平均库仑效率超过 99.9%摄氏度。综合分析进一步揭示了 NMC811 正极和石墨负极之间的阻抗匹配，这是由于形成了类似的富含氟化锂的界面，从而有效避免了低温下的锂电镀。这种电解质设计原理可以扩展到其他在极端条件下运行的碱金属离子电池。